Regulator



Dec. 3, 1941.

J. F. KOVALSKY REGULATOR Filed Feb. 23', 1939 5 Sheets-Sheet 1WiTNESSES:

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ATTORNEY Dec. 2, 1941. J. F. KOVALSKY 2,264,986

REGULATOR Filed Feb. 23, 1939 3 Sheets-Sheet 2 Fig". 5,

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1941- J. F. KOVALSKY' 2,264,986

I REGULATOR Filed Feb. 25, 1939 s Sheets-Sheet a Fllq. 2

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ATTORNEY Patented Dec. 2, 1941 REGULATOR Joseph F. Kovalsky, TurtleCreek, Pa., assignor to Westinghouse Electric & Manufacturing Company,East Pittsburgh, Pa., a corporation of Pennsylvania Application February23, 1939, Serial No. 257,949

Claims.

My invention relates to regulators of the type wherein the regulatedquantity is controlled by a primary control device that is actuated bythe joint action of an electromagnet and mechanical biasing means, andparticularly to means for adjusting the sensitivity of such primarycontrol device.

My invention is applicable to regulators of the type disclosed andclaimed in a copending application of C. R. Hanna and S. Sentipal,Serial No. 203,876, filed March 23, 1938, for Regulators, and assignedto the same assignee as this application, which application becamePatent No. 2,246,301 on June 17, 1941. The magnetic structure foroperating the control element may correspond to that disclosed andclaimed in an application of R. A. Geiselman, Serial No. 219,527, filedJuly 16, 1938, for Regulators, and assigned to the same assignee as thisapplication, which application became Patent No. 2,235,400 on March 18,1941.

In regulators of the character referred to a rheostatic control deviceis employed which includes a plurality of leaf springs arranged in astack and connected to a plurality of spaced points along an associatedresistor for varying the effective value of the resistor for controllingan electric circuit. The leaf springs are normally insulated from eachother and carry contact members at one end which are free to move andwhich are normally biased against a stop which spaces them in suchmanner as to effect a separation of the several contact members carriedby their free ends. A driving member is provided that is actuated by theresultant mechanical and electromagnetic forces exerted by the leafsprings, an electromagnet, and a biasing spring which opposes the forceof the electromagnet. The driving member is adapted to move the severalleaf springs together with their associated contact members relative tothe stop to effect a sequential engagement thereof, and to shunt varyingportions of the resistor connected between the several leaf springs tothereby vary the effective value of the resistor.

In order that the regulating device remains stationary at a particularposition corresponding to a particular efiective value of the resistor,it is necessary that there be a slight variation between the pull curveof the electromagnet and the load curve for opposing its motion.Otherwise, the moving element of the regulator would remain stationaryin any position instead of in one position only for a given excitationof the regulator winding and a corresponding given pull on the armature.

In the past, the degree of sensitivity of regulators of the characterdescribed have been adjusted by varying the pull on the spring opposingthe force of the actuating electromagnet. In varying this force, thecurrent through the electromagnet required to balance the spring forceis changed, and the effective range of the voltage adjusting rheostatconnected in series therewith for adjustingthe particular voltage to beregulated is correspondingly changed, thus limiting the voltageadjustment that may be made thereby.

It is an object of my invention to provide means for adjusting thesensitivity of a regulator of the class described without the necessityof increasing or decreasing the balance point or the winding currentcorresponding to a predetermined pull of the actuating magnet on itsarmature.

Other objects and advantages of my invention will appear from thefollowing description of preferred embodiments thereof, reference beingmade to the accompanying drawings, in which:

Figure 1 is a diagrammatic view of circuits and apparatus comprising aregulator system employing the invention;

Fig. 2 is a side elevational view of the primary control element;

Fig. 3 is a side elevational view of a portion of the primary controlregulator element illustrating one embodiment of the invention foradjusting the sensitivity thereof;

Fig. 4 is a diagram for explaining the operation of the structure shownin Fig. 3;

Fig. 5 is a side elevational view of another embodiment of theinvention;

Fig. 6 is a diagram for aiding in the explanation of the operation ofthe structure shown in Fig. 5; and,

Figs. '7 and 8 are curves for illustrating characteristics of theprimary control regulator element.

Referring to Figure 1, an electric generator I is illustrated having anarmature winding 2 that is connected to circuit conductors 3 and 4, anda field winding 5 that is energized from the armature winding through acircuit including conductor 6, regulating resistor I, conductor 8, and afield adjusting rheostat 9. Spaced points along the resistor I areconnected by conductors 12 to a plurality of leaf springs 13,corresponding ends of which are stationary and insulated from oneanother by thin layers of insulating material H, such as fish paper, andheld together within a bracket l5 by a pressure plate I6 and retainingthe ends thereof are adapted to engage aniri-L M clined surface [9 of astop 22 in sequence as the group of springs is moved toward the left to7 permit separation of the adjacent contact buttonsl8. For varying theeffective value of the resistor I, a driving member 23 is .provided andcarried by a lever 24 that is so mounted as to be moved about a pivot 25in accordance with the resultant} forcesexertedthereon by an armature 32and a tension spring 26, one end 21 of which is attached to the lever 24and-the other end 28 of which is attached to an abutment '29; Thearmature 32 of magnetic material is mounted on the lever 24 andpositioned in an air gap 33 between the'ends of a C-shaped corestructure 34 having a winding leg about which a winding 35 is placed andconnected to be energized from conductors 3 and 4'in accordance with thevoltage to be regulated. a

The circuit of the winding 35 extends from line conductor 3 throughconductor 36, voltage adjusting rheostat 31, conductor 38, the winding35, conductor 39, the winding 42 of a stabilizing transformer 43, to theline conductor 4. The primary winding 44 of the stabilizing transformer43 is connected by conductors 45 and 46 to be energized in accordancewith the voltage across the field winding 5 of the generator I. tointroduce stabilizing voltage impulses into the regulator controlcircuit. during changes in generator voltage. Astop 41 is provided onthe lever 24 to limit the movement of the driving member 23 toward theright as shown in Fig. 1.

Referring to Fig. 2, the pivot line 25 is the plane of intersection offlatleaf springs 48, and leaf springs 53. The springs 48 extendhorizontally from a bracket 49 carried onthe core structure 32, and abracket 52 carried on the leaf arm Z l. The vertically positioned leafsprings 53 likewise extend between the brackets 49 and 52. The armature32 is positioned in a space between opposite endsof the C-shaped core 34providing two gaps 33 on opposite faces of the armature 32. The sum ofthe two air gaps is thus maintained constant as the overlap between theopposite armature faces and the ends of the corev structure 34 vary'withvarying position of the lever 24. The inner surface 54 of the armature32 is shaped to effect a varying pull with change in position sufficient to compensate for the varying load on the lever 24 occasioned by thevarying force of the increasing number of springs 13 exerted against thedriving member 23 as this member moves toward the right, and to alsocompensate for the change in tension of the spring26. V

, In Fig. 1, the lever 24 is shown in its extreme right position limitedby the stop 41 and the driving member 23 is suiiiciently toward theright. to raise each of th leaf springs [3 from the surface 19 of thestop 22, causing the several contact buttons [8 tobe in engagement withtween conductors l2 of the resistor i. As the generator voltage buildsup and the energization of the winding 35 increases, the pull of thearmature 32 against the force of the spring 26 increases, until it issufiicient to move the lever 24 in acounter-clockwise direction aboutthe pivot 25, and permit certain of the leaf springs 13 to engage thestop 22 in sequence, those shown at the right of the stack of leafsprings engaging first. When .a sufficient number of the leaf springs l3have engaged the stop 22 to remove "the shunt circuit therethrough froma sufficient number of the portions of the resistor 1 to increase theeffective value of this resistor, the

lever 24 remains stationary in a position to maintain the'd'esiredvoltage between circuit conductors 3 and 4. As the generator voltagevaries in one direction or th other from its desired value,

- the energization of the winding 35 correspondthe correspondingbuttonsonthe adjacent leaf springs to short circuit the .seyeralportionsbeingly varies to cause the lever 24 to move so as to .vary the numberof leaf springs I3 resting against the stop 22 to increase or decreasethe effective value of the resistor 1 sufli-ciently to correct forvariations in the generator voltage from the desired value. 7

Referring to Fig. '7, curves 51, 58 and 59 represent pull curves, thatis, the effective moment or torque exerted on the lever 24 about thepivot point 25 by the armature 32 upon varying positions from theinnermost position of the armature 32 as it moves toward the left, asviewed in Figs. 1 and 2. The range in values of torque shown on thecurve represents-relatively high values such as from full torque to,say, full torque to best show the nature of the curves. As previouslyexplained, the shape of the armature 32 is such that as it movesoutwardly or toward the left for a substantially constant current value,the pull decreases so as to compensate for the increasing load on thespring 26 resulting from the increasing number of leaf springs I3 thatare raised from engagement with the stop member 22, and also tocompensate for the decreasing force of the spring 26 as its length isslightly shortened. The three dotted line curves 62,. 63 and 64represent load curves, that is, the mechanical torque which acts as aload on the electromagnet. The three load curves 62, 63 and 54 exert thesame torque as that exerted by the electromagnet as shown by curves 51,58 and, respectively, when the armature 32 is in itsinnermost positionand vary progressively from the pull curve as the distance from thatposition increases. The three curves 51,58 and 59 may, for example,represent the pull curve of the regulating unit shown in Fig. 2 forcurrent values of .11, .10 and .09 ampere through the winding 35 overthe range of movement of the armature 32. It will be noted that as thecurrent through the coil is decreased, the range or percentage variationof the load curve with respect to the this current effects a variationin the voltage drop across the voltage adjusting rheostat 31, effectingan inaccuracy in the regulator until this rheostat is readjusted, andlikewise limiting the range of voltageadjustment permissible by .therheostat 31.

In accordance with my inventionmeans are provided for varying thesensitivity of jthe llljr' mary regulating element without changing thepull curve. This may be done by mounting the abutment 29 on which oneend of the spring 26 is attached, upon a support 65, as shown in Figs. 2and 3 by any suitable adjusting means, such as a screw 66 extendingthrough a slot 61 in the abutment 29 to permit vertical adjustment ofthe eyelet 28 carrying one end of the spring 26. In Fig. 3, the eyeletis shown in three elevations A, B and G, respectively, the effect ofwhich is most easily understood by referring to Fig. 4, in which thearrows a, b and c represent, respectively the direction of the force ofthe spring 26 in the three positions. The lower arrow in Fig. 4represents the pull of the magnet on the armature 32 about the pivotpoint 25. It will be noted that when the eyelet 28 is in position A, theforce exerted in the direction of the arrow a acts about a lever arm 69.If the position of the eyelet 28 is moved to position B, the force ofthe spring 26 acts in a direction represented by the arrow b in Fig. 4through a lever arm l which is less than the lever arm 69. Again, if theeyelet 28 is moved to the position C, the force of the spring 26 acts inthe direction of the arrow 0 in Fig. 4 through a lever arm about thepivot line 25 represented by the dotted arrow line "H, which is lessthan the lever arm 10. If, therefore, the tension on the spring 26 inany one of the three positions A, B or C is a so adjusted that thetorque or load is the same when the armature 32 is in its extreme rightposition, as shown in Figs. 1, 2 and 3, the three load curves A, B and Cas shown in Fig. 8, will just balance the pull curve 68 in that positionand the adjustment of the spring will not affect the pull curve. As thearmature moves from its zero position on the diagram of Fig. 8, or in aclockwise direction about its pivot line 25 as shown in Figs. 1, ,2 and3, the curves A, B and C represent the varying loadings in the threepositions of the spring 26. These three curves all start at the samepoint on the curve 68 and droop progressively further below the curve 68because of the decreasing lever arms 69, and H as shown in Fig. 4.

Referring to Figs. 5 and 6, another embodiment of the invention isillustrated, the general construction of the regulating control elementbeing the same as that shown in Figs. 1, 2 and 3, except that instead ofproviding for varying the fixed end of the spring 26 connected to theeyelet 28 vertically in order to change the direction of the force ofthe spring 26 in the manner just described, the opposite end of thespring 28 is connected to an eyelet 12 that is carried by a bracket 13on the lever 24 and held by a nut 14. The eyelet 12 is adjustablehorizontally, or in a direction corresponding to the axis of the spring26 so that the point of contact 15 of the spring to the eyelet may bevaried, the effect of which is easiest understood by referring to Fig.6.

If the point 15 is in its leftmost position as shown in Fig. 6, so thatits direction of travel toward the right will be along the are 16, thehorizontal movement effected by a predetermined arc may be representedby the distance 11 and the direction of the force of the spring 26 willmove from that represented by the line 18 to the direction of the line19 as the point 15 moves through the are '16, thus increasing the leverarm of the axis of pull about the pivot point from that represented bythe dotted arrow 8| to that represented by the dotted arrow 82, so thatthe efiect of the loading is relatively high corresponding, for example,to that represented by curve A in Fig. 8. If, on the other hand, thepoint of connection 15 between the left end of the spring 26 and theeyelet 12 is represented by the point 15 in Fig. 6, its horizontalmovement through an are 83 corresponding in angular degrees to the are16 will result in a greater horizontal movement of the point 15 shown bydistance 84, thus resulting in a greater decrease in the force of thespring 23 over the same angular movement. Also in the position chosen,the point '15 moves substantially directly along the original axis ofthe spring 2t, that is, along the line 18, so that the distance of thisforce from the pivot point 25 does not change appreciably as in thefirst chosen instant, resulting in a load curve such, for example, asthe curve C in Fig. 8. For intermediate points of adjustment of theconnection of the spring 26 to the eyelet 12 between that represented bypoints 15 and 15 in Fig. 6, correspondingly different load curvesbetween those illustrated by curve A and C" in Fig. 8 may beestablished. All of these load curves represent adjustments of theregulating element in which the load on the magnet is the same for thezero or starting point of movement of the armature 32.

Referring to Fig. 8, curves 9! and 92 represent load curvescorresponding to progressively lesser values of current flowing in thewinding 35, with correspondingly lesser values of pull or the armature32 throughout the range in movement of the armature than the current andpull represented by curve 68. If for example, the regulator is adjustedto have a 4% droop in load curve below the pull curve 68 throughout itsrange of movement, corresponding to load curve A, the regulator lever 24will be at rest at the position represented by the point 93 when thecurrent corresponds to the value represented by curve 9|. If theregulator is adjusted for a 6% or 8% droop in load, curves B and C,respectively, the regulator will balance in the positions represented bypoints 94 and 95 respectively in Fig. 8. Similarly, with a current valuecorresponding to the pull curve 92, the regulator will balance inpositions represented by points 96, 9'1 and 93 respectively, for thethree load curve adjustments represented by curves A, B and C.

Many modifications may be made in the arrangement of parts within thespirit of my invention, and I do not wish to be limited otherwise thanby the scope of the appended claims.

I claim as my invention:

1. In a regulating system for controlling an electric quantity, 3.primary control device having a plurality of contact members, means foractuating said contact members in sequence comprising a driving membermounted for movement about an axis, biasing means for urging saiddriving member in one direction about said axis, electro-responsivemeans for urging said driving member in the opposite direction aboutsaid axis, and means for varying the effective lever arm through whichthe force of said biasing means acts for adjusting the variation insensitivity of the device throughout its range of operation.

2. In a regulating system for controlling an electric quantity, aprimary control device having a plurality of contact members, means foractuating said contact members in sequence comprising a driving membermounted for movement about an axis, biasing means for urging saiddriving member in one direction about said axis, electro-responsivemeans for urging said driving member in the opposite direction aboutsaid axis, and means for varying the effective lever arm through whichthe force of said biasing means acts for adjusting the variation insensitivity of the regulator throughout its range of operationcomprising means for adjusting the direction of application of the forceof the biasing means to the movable member with respect to the radius ofmovement of the point of application thereof about the axis of movement.

3 In a regulating system for controlling an electric quantity, a primarycontrol device having a plurality of contact members, means foractuating said contact members in sequence comprising a driving membermounted for movement about an axis, biasing means for urging saiddriving member in one direction about said axis, electro-responsivemeans for urging said driving member in the opposite direction aboutsaid axis, and means for varying the effective lever arm through whichthe force of said biasing means acts for adjusting the variation insensitivity of the regulator throughout its range of operationcomprising means for adjusting the point along the axis of applicationof the force of the biasing means at which the force is applied to themoving member.

4. In a regulating system for controlling an electric quantity, aprimary control device having a plurality of contact members, means foractuating said contact members in sequence comprising a lever mountedfor movement about an axis and a driving member carried thereby, biasingmeans extending substantially at right angles to the lever for urgingthe lever in one direction about said axis, electroresponsive means forurging said driving member in the opposite direction about said axis,and means for varying the effective lever arm through which the force ofsaid biasing means acts for adjusting the variation in sensitivity ofthe regulator throughout its range of operation comprising alongitudinally adjustable supporting arm for one end of the biasingmeans positioned substantially parallel to the lever for adjusting thedirection of application of the force of the biasing means to themovable member with respect to. the radius of movement of the point ofapplication thereof about the axis of movement.

5. In a regulating system for controlling an electric quantity, aprimary .control device having a plurality of contact members, means foractuating said contact members in sequence comprising a lever mountedfor movement about an axis and a driving member carried thereby, biasingmeans extending substantially at right angles to the lever for urgingthe lever in one direction about said axis, electroresponsive means forurging said driving member in the opposite direction about said axis,and means for varying the efiective lever arm through which the force ofsaid biasing means acts for adjusting the variation in sensitivity ofthe regulator throughout its range of operation comprising means foradjusting the point along the aXis of application of the force of thebiasing means at which the force is applied to the moving lever.

JOSEPH F. KOVALSKY.

